The Arctic winter is cold, snowy, and dark. The barren landscape is covered by a layer of snow that stretches to the horizon, with nothing to disrupt it but jagged rocks. There are only a few plants and no sunlight. And yet, there are animals hardy enough to survive this bleak environment: the arctic wolf, hare, cod, and fox; the snowy owl, polar bear, ringed seal, and Peary caribou, all inextricably linked together in the chain of life. With lyrical...